Usefulness of uterine artery Doppler velocimetry as a predictor for hypertensive disorders in pregnancy in women with prehypertension before 20 weeks gestation

Hypertensive disorders of pregnancy (HDP) is major complication of maternal-fetal outcomes in obstetric field. Although HDP is mainly defined by high blood pressure, the information about the relationship between prehypertension (preHTN, 120-139mmHg and 80-89mmHg) and HDP development is limited. The objective of this study is to determine the usefulness of preHTN before 20 weeks gestation and uterine artery (UtA) Doppler velocimetry as a predictor of HDP. A total of 2039 singleton pregnant women who had received continuous prenatal care were included in this study. The participants were classified into 2 groups based on the highest blood pressure (BP) under 20 gestational weeks as defined by the Joint National Committee 7: Normotensive (n = 1816) and preHTN pregnant women (n = 223). All preHTN pregnant women were assessed using UtA Doppler velocimetry, and the numbers of preHTN assessments were recorded. The risk of HDP was assessed in the PreHTN groups through patient history and Doppler velocimetry. Compared to normotensive patients, a total of 223 preHTN patients had a higher risk of preeclampsia (OR: 2.3; CI: 1.2–4.3), gestational hypertension (OR: 3.3; CI: 2.0–5.4) and any HDP (OR: 3.0; CI: 2.0–4.5). In the preHTN group, 134 (60.1%) patients had preHTN measured at least twice and 89 (39.9%) patients had preHTN. The results showed that two or more preHTN measurements have high sensitivity for predicting HDP (OR: 1.9; CI: 1.0–3.1; sensitivity: 83.8%; specificity: 47.2%). Additionally, the combination of abnormal UtA Doppler velocimetry results and at least two preHTN measurements showed a high accuracy in predicting HDP (OR: 2.9; CI: 1.1–4.1; sensitivity: 67.6%; specificity: 98.4%). In conclusion, close BP monitoring and recording of every preHTN event are important for pregnant women with preHTN history, and UtA Doppler examination in those women during the 2(nd) trimester can be a further aid in determining the risk of HDP.